Organic solar cell and photodetector materials and devices
Narrow bandgap n-type small molecules are attracting attention in the near-infrared organic optoelectronics field, due to their easy tunable energy band with a molecular design flexibility. However, only a few reports demonstrate narrow bandgap non-fullerene acceptors (NFAs) that perform well in organic solar cells (OSCs), and the corresponding benefits of NFA photodiodes have not been well investigated in organic photodetectors (OPDs). Here, the ultra-narrow bandgap NFAs CO1-4F, CO1-4Cl and o-IO1 were designed and synthesized for the achieved efficient near-infrared organic photodiodes such as solar cells and photodetectors. Designing an asymmetrical CO1-4F by introducing two different π-bridges including alkylthienyl and alkoxythienyl units ultimately provides an asymmetric A-D′-D-D″-A molecular configuration. This enables a delicate modulation in energy band structure as well as maintains an intense intramolecular charge transfer characteristic of the excited state.
1 . A composition of matter, comprising:
an organic semiconducting molecule having an A-D′-D-D″-A structure, wherein:
D′ is a first donor moiety,
D is a second donor moiety different from D′,
D″ is a third donor moiety different from D and D′ to make the organic semiconducting molecule asymmetric, and
A is an acceptor moiety; and
wherein D′ and D″ are selected from:
and
wherein each R 2 , R 3 , R 4 , R 5 , R 6 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; Z is O, S, Se, or N—R 6 , R 4 can be Z—R 2 ; R 5 can be the same; and Y is O, S, Se, or N—R 6 and R 3 is different from Z—R 2 ;
wherein D is one of the following:
where each R 1 and R 3 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; Y is O, S, Se or N—R 3 ; each Ar is independently a substituted or non-substituted aromatic functional group, or each Ar is independently nothing and the valence of its respective thiophene ring is completed with hydrogen, or
wherein D is one of the following:
where each R 1 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; and Y is O, S, Se or N—R 3 , or
wherein D is one of the following:
where each R, R 1 , R 2 and R 3 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; and Y is O, S, Se or N—R 3 ; and
A has the structure:
wherein EWG is any electron withdrawing group.
2 . The composition of matter of claim 1 , wherein:
D is a donor moiety comprising a dithiophene, and
A is an acceptor moiety comprising (3-oxo-2,3-dihydro-1H-inden-1-ylidene) malononitrile (IC).
3 . The composition of matter of claim 1 , wherein the organic semiconducting molecule has a HOMO in a range of −5.0 eV to −5.5 eV, a LUMO in a range of −3.8 eV to −4.3 eV, and a bandgap in a range of 1.0 eV to 1.4 eV.
4 . The composition of matter of claim 1 , wherein the organic semiconducting molecule has the structure (or an isomer thereof):
where each R 1 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; and each Ar is independently a substituted or non-substituted aromatic functional group or each Ar is independently nothing and the valence of its respective thiophene ring is completed with hydrogen.
5 . The composition of matter of claim 1 , wherein the organic semiconducting molecule has the structure (or isomers thereof):
where each R 1 , R 2 , R 3 , R 4 , R 5 , R 6 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain but R 3 is different from Z—R 2 ; R 4 can be the same as Z—R 2 ; R 5 can be the same as R 3 ; X is C, Si, Ge, Nor P; Y is O, S, Se, or N—R 6 , Z is O, S, Se, or N—R 6 ; each Ar is independently a substituted or non-substituted aromatic functional group, or each Ar is independently nothing and the valence of its respective thiophene ring is completed with hydrogen.
6 . The composition of matter of claim 1 , wherein the organic semiconducting molecule has the structure (or an isomer thereof):
where each R, R 2 , R 3 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P and R 3 is different from O—R 2 .
7 . The composition of matter of claim 1 , wherein the organic semiconducting molecule has the structure (or an isomer thereof):
8 . The composition of matter of claim 1 wherein Ar′ is one of the following:
9 . The composition of matter of claim 1
wherein D′ and D″ are selected from different ones of:
10 . The composition of matter of claim 1 , wherein:
D′ comprises an alkyl moiety or hydrogen and D″ comprises an alkoxy moiety or
D′ comprises an alkoxy moiety and D″ comprises an alkyl moiety or hydrogen.
11 . The composition of matter of claim 1 , wherein Y is O, S, or N—R 6 and R 3 is different from Z—R 2 .
12 . The composition of matter of claim 1 , wherein:
D′ is any of the structures with Z=O or S and D″ is
where R 3 and R 5 are each independently alkyl or hydrogen, or
D″ is any of the structures with Z=O or S and D′ is
where R 3 and R 5 are each independently alkyl or hydrogen.
13 . A device comprising an active region including the composition of matter of claim 1 , wherein the organic semiconducting molecule is an electron acceptor.
14 . The device of claim 13 , wherein:
the active region comprises each of the electron acceptors forming a heterojunction with an electron donor comprising a second organic semiconducting molecule, and
the active region has a thickness of at least 300 nanometers or in a range of 200 nm to 1 micrometer.
15 . The device of claim 13 , further comprising:
a cathode;
an anode; and
the active region between the cathode and the anode; and wherein:
holes and electrons are generated in the active region in response to electromagnetic radiation incident on the active region,
the electrons are collected in the electron acceptor and are transmitted through to the cathode, and
the holes are collected in the electron donor and transmitted through to the anode.
16 . The device of claim 15 , further comprising:
a hole blocking layer between the cathode and the active region, and
an electron blocking layer between the anode and the active region.
17 . The device of claim 13 , wherein the device is an organic solar cell outputting current in response to sunlight absorbed in the active region.
18 . The device of claim 13 , wherein the device is a photodetector outputting current in response to infrared electromagnetic radiation absorbed in the active region.
19 . The device of claim 13 , wherein each of the electron donors comprise at least one compound selected from PTB7-Th, another BDT based polymer, a CPDT based polymer, a DPP based polymer, or a DTP based polymer.
20 . The device of claim 13 , further comprising:
a plurality of the electron donors and a plurality of the organic semiconducting molecules that are phase separated, wherein the organic semiconducting molecules are disposed in a hierarchical network and the electron donors comprising the second organic semiconducting molecules occupy spaces in the hierarchical network, and wherein the hierarchical network comprises larger mid rib shaped regions connected by smaller or thinner regions.
21 . A composition of matter, comprising:
an organic semiconducting molecule having an A-D′-D-D″-A structure, wherein:
D′ is a first donor moiety,
D is a second donor moiety different from D′,
D″ is a third donor moiety different from D and D′ to make the organic semiconducting molecule asymmetric, and
A is an acceptor moiety; and
wherein D′ and D″ are selected from:
and
wherein each R 2 , R 3 , R 4 , R 5 , R 6 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; Z is O, S, Se, or N—R 6 , and Y is O, S, or N—R 6 ,
wherein D is one of the following:
where each R 1 and R 3 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; Y is O, S, Se or N—R 3 ; each Ar is independently a substituted or non-substituted aromatic functional group, or each Ar is independently nothing and the valence of its respective thiophene ring is completed with hydrogen, or
wherein D is one of the following:
where each R 1 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; and Y is O, S, Se or N—R 3 , or
wherein D is one of the following:
where each R, R 1 , R 2 and R 3 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; and Y is O, S, Se or N—R 3 ; and
A has the structure:
wherein EWG is any electron withdrawing group.
22 . A method of making a device, comprising:
solution processing a composition of matter including electron donor molecules and electron acceptor molecules of the structure A-D′-D-D″-A structure, wherein:
D′ is a first donor moiety,
D is a second donor moiety different from D′,
D″ is a third donor moiety different from D and D′ to make the organic semiconducting molecule asymmetric, and
A is an acceptor moiety,
combining the composition of matter with an additive so that:
the plurality of the electron donor molecules and the plurality of electron acceptor molecules are phase separated,
the electron acceptor molecules are disposed in a hierarchical network and
the electron donor molecules occupy spaces in the hierarchical network; and
wherein D′ and D″ are selected from:
and
wherein each R 2 , R 3 , R 4 , R 5 , R 6 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; Z is O, S, Se, or N—R 6 , R 4 can be Z—R 2 ; R 5 can be the same; and Y is O, S, Se, or N—R 6 ; and R 3 is different from Z—R 2 ;
wherein D is one of the following:
where each R 1 and R 3 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; Y is O, S, Se or N—R 3 ; each Ar is independently a substituted or non-substituted aromatic functional group, or each Ar is independently nothing and the valence of its respective thiophene ring is completed with hydrogen, or
wherein D is one of the following:
where each R 1 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; and Y is O, S, Se or N—R 3 , or
wherein D is one of the following:
where each R, R 1 , R 2 and R 3 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain; X is C, Si, Ge, N or P; and Y is O, S, Se or N—R 3 ; and
A has the structure:
wherein EWG is any electron withdrawing group.